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authorWill Drewry <wad@chromium.org>2012-04-13 01:48:00 +0400
committerJames Morris <james.l.morris@oracle.com>2012-04-14 05:13:21 +0400
commita0727e8ce513fe6890416da960181ceb10fbfae6 (patch)
tree300fc5c620c4e90915985504007d9e66bc896d14 /arch/x86
parentacf3b2c71ed20c53dc69826683417703c2a88059 (diff)
downloadlinux-a0727e8ce513fe6890416da960181ceb10fbfae6.tar.xz
signal, x86: add SIGSYS info and make it synchronous.
This change enables SIGSYS, defines _sigfields._sigsys, and adds x86 (compat) arch support. _sigsys defines fields which allow a signal handler to receive the triggering system call number, the relevant AUDIT_ARCH_* value for that number, and the address of the callsite. SIGSYS is added to the SYNCHRONOUS_MASK because it is desirable for it to have setup_frame() called for it. The goal is to ensure that ucontext_t reflects the machine state from the time-of-syscall and not from another signal handler. The first consumer of SIGSYS would be seccomp filter. In particular, a filter program could specify a new return value, SECCOMP_RET_TRAP, which would result in the system call being denied and the calling thread signaled. This also means that implementing arch-specific support can be dependent upon HAVE_ARCH_SECCOMP_FILTER. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Will Drewry <wad@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Eric Paris <eparis@redhat.com> v18: - added acked by, rebase v17: - rebase and reviewed-by addition v14: - rebase/nochanges v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc v12: - reworded changelog (oleg@redhat.com) v11: - fix dropped words in the change description - added fallback copy_siginfo support. - added __ARCH_SIGSYS define to allow stepped arch support. v10: - first version based on suggestion Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/ia32/ia32_signal.c4
-rw-r--r--arch/x86/include/asm/ia32.h6
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a69245ba27e3..0b3f2354f6aa 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -67,6 +67,10 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
break;
+ case __SI_SYS >> 16:
+ put_user_ex(from->si_syscall, &to->si_syscall);
+ put_user_ex(from->si_arch, &to->si_arch);
+ break;
case __SI_CHLD >> 16:
if (ia32) {
put_user_ex(from->si_utime, &to->si_utime);
diff --git a/arch/x86/include/asm/ia32.h b/arch/x86/include/asm/ia32.h
index ee52760549f0..b04cbdb138cd 100644
--- a/arch/x86/include/asm/ia32.h
+++ b/arch/x86/include/asm/ia32.h
@@ -144,6 +144,12 @@ typedef struct compat_siginfo {
int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
int _fd;
} _sigpoll;
+
+ struct {
+ unsigned int _call_addr; /* calling insn */
+ int _syscall; /* triggering system call number */
+ unsigned int _arch; /* AUDIT_ARCH_* of syscall */
+ } _sigsys;
} _sifields;
} compat_siginfo_t;